
<h1><span class="yiyi-st" id="yiyi-12">numpy.roll</span></h1>
        <blockquote>
        <p>原文：<a href="https://docs.scipy.org/doc/numpy/reference/generated/numpy.roll.html">https://docs.scipy.org/doc/numpy/reference/generated/numpy.roll.html</a></p>
        <p>译者：<a href="https://github.com/wizardforcel">飞龙</a> <a href="http://usyiyi.cn/">UsyiyiCN</a></p>
        <p>校对：（虚位以待）</p>
        </blockquote>
    
<dl class="function">
<dt id="numpy.roll"><span class="yiyi-st" id="yiyi-13"> <code class="descclassname">numpy.</code><code class="descname">roll</code><span class="sig-paren">(</span><em>a</em>, <em>shift</em>, <em>axis=None</em><span class="sig-paren">)</span><a class="reference external" href="http://github.com/numpy/numpy/blob/v1.11.3/numpy/core/numeric.py#L1335-L1401"><span class="viewcode-link">[source]</span></a></span></dt>
<dd><p><span class="yiyi-st" id="yiyi-14">沿给定轴滚动数组元素。</span></p>
<p><span class="yiyi-st" id="yiyi-15">滚动超过最后位置的元素在第一个重新介绍。</span></p>
<table class="docutils field-list" frame="void" rules="none">
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<tr class="field-odd field"><th class="field-name"><span class="yiyi-st" id="yiyi-16">参数：</span></th><td class="field-body"><p class="first"><span class="yiyi-st" id="yiyi-17"><strong>a</strong>：array_like</span></p>
<blockquote>
<div><p><span class="yiyi-st" id="yiyi-18">输入数组。</span></p>
</div></blockquote>
<p><span class="yiyi-st" id="yiyi-19"><strong>shift</strong>：int</span></p>
<blockquote>
<div><p><span class="yiyi-st" id="yiyi-20">元素移动的位置数。</span></p>
</div></blockquote>
<p><span class="yiyi-st" id="yiyi-21"><strong>axis</strong>：int，可选</span></p>
<blockquote>
<div><p><span class="yiyi-st" id="yiyi-22">元素移动的轴。</span><span class="yiyi-st" id="yiyi-23">默认情况下，数组在移位前展平，之后将恢复原始形状。</span></p>
</div></blockquote>
</td>
</tr>
<tr class="field-even field"><th class="field-name"><span class="yiyi-st" id="yiyi-24">返回：</span></th><td class="field-body"><p class="first"><span class="yiyi-st" id="yiyi-25"><strong>res</strong>：ndarray</span></p>
<blockquote class="last">
<div><p><span class="yiyi-st" id="yiyi-26">输出数组，形状与<em class="xref py py-obj">a</em>相同。</span></p>
</div></blockquote>
</td>
</tr>
</tbody>
</table>
<div class="admonition seealso">
<p class="first admonition-title"><span class="yiyi-st" id="yiyi-27">也可以看看</span></p>
<dl class="last docutils">
<dt><span class="yiyi-st" id="yiyi-28"><a class="reference internal" href="numpy.rollaxis.html#numpy.rollaxis" title="numpy.rollaxis"><code class="xref py py-obj docutils literal"><span class="pre">rollaxis</span></code></a></span></dt>
<dd><span class="yiyi-st" id="yiyi-29">向后滚动指定的轴，直到它位于给定位置。</span></dd>
</dl>
</div>
<p class="rubric"><span class="yiyi-st" id="yiyi-30">例子</span></p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="n">x</span> <span class="o">=</span> <span class="n">np</span><span class="o">.</span><span class="n">arange</span><span class="p">(</span><span class="mi">10</span><span class="p">)</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">np</span><span class="o">.</span><span class="n">roll</span><span class="p">(</span><span class="n">x</span><span class="p">,</span> <span class="mi">2</span><span class="p">)</span>
<span class="go">array([8, 9, 0, 1, 2, 3, 4, 5, 6, 7])</span>
</pre></div>
</div>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="n">x2</span> <span class="o">=</span> <span class="n">np</span><span class="o">.</span><span class="n">reshape</span><span class="p">(</span><span class="n">x</span><span class="p">,</span> <span class="p">(</span><span class="mi">2</span><span class="p">,</span><span class="mi">5</span><span class="p">))</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">x2</span>
<span class="go">array([[0, 1, 2, 3, 4],</span>
<span class="go">       [5, 6, 7, 8, 9]])</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">np</span><span class="o">.</span><span class="n">roll</span><span class="p">(</span><span class="n">x2</span><span class="p">,</span> <span class="mi">1</span><span class="p">)</span>
<span class="go">array([[9, 0, 1, 2, 3],</span>
<span class="go">       [4, 5, 6, 7, 8]])</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">np</span><span class="o">.</span><span class="n">roll</span><span class="p">(</span><span class="n">x2</span><span class="p">,</span> <span class="mi">1</span><span class="p">,</span> <span class="n">axis</span><span class="o">=</span><span class="mi">0</span><span class="p">)</span>
<span class="go">array([[5, 6, 7, 8, 9],</span>
<span class="go">       [0, 1, 2, 3, 4]])</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">np</span><span class="o">.</span><span class="n">roll</span><span class="p">(</span><span class="n">x2</span><span class="p">,</span> <span class="mi">1</span><span class="p">,</span> <span class="n">axis</span><span class="o">=</span><span class="mi">1</span><span class="p">)</span>
<span class="go">array([[4, 0, 1, 2, 3],</span>
<span class="go">       [9, 5, 6, 7, 8]])</span>
</pre></div>
</div>
</dd></dl>
